System for persistent and delayed allocation object reference in an object oriented environment

In an object oriented computing environment operating on a data processor containing a main memory and having a direct access storage device for persistently storing data objects, in which a plurality of data objects are categorized into one or more classes which define methods of the categorized classes, and in which messages containing an object reference data structure are sent by the data processor to at least one object to perform at least one action upon said object, said object reference data structure having an object type field, an object class identification field, an object instance identification field and an access address field, a method for handling unresolved object references comprising the steps of:

• searching an object management table using the object instance identification field of said object reference data structure to determine if there is an entry pointing to an object instance for the referenced object in main memory;
• if an entry is found in said object management table for the referenced object, updating the access address field in the object reference data structure so that it points to said object instance for the referenced object;
• if an entry for the referenced object is not found in said object management table, examining the object class identification field of said object reference data structure to determine if the referenced object is persistent;
• if the referenced object is persistent, allocating an empty instance frame in main memory for the referenced object and sending a request to a materialize method of the referenced object to fetch the referenced object from the direct access storage device to main memory;
• and
• adding an entry to the object management table for the fetched referenced object if it is successfully fetched.

In an object oriented computing environment operating on a data processor containing a main memory and having a direct access storage device for persistently storing data objects, in which a plurality of data objects are categorized into one or more classes which define methods of the categorized classes, and in which messages containing an object reference data structure are sent by the data processor to at least one object to perform at least one action upon said object, said object reference data structure having an object type field, an object class identification field, an object instance identification field and an access address field, a method for handling resolved object references comprising the steps of:

• validating the access address field of the object reference data structure by comparing the object type field, the object class identification field, and the object instance identification field of said object reference data structure with corresponding data field entries in the object management table to find a match;
• if an entry is found in the object management table that matches the object type field, the object class identification field, and the object instance identification field of said object reference data structure, using the access address field of said matching object management table entry to identify the location in main memory of said referenced object;
• and
• if no entry is found in the object management table that matches the object type field, the object class identification field, and the object instance identification field of said object reference, setting the access address field of said object reference data structure to a null value and invoking a procedure to further handle the referenced object as an unresolved object reference.